Kinematic v_R-v_ϕ space for the G3RV2 stars in the SNd cross-matched with Galah (left), AstroNN (centre), and LAMOST (right). Density distribution (first row), colour-coded by the mean [Fe/H] (second row), the mean [Fe/H] for thin-disk stars (low-α sequence, third row), and the residual [Fe/H] distribution for low-α stars (bottom row). The v_R-v_ϕ features are well established with the higher mean metallicity (δ[Fe/H] ≈ 0.05 dex), and two groups of kinematic features are separated by low-[Fe/H] gaps behind the corotation (Hercules streams) and the OLR (Sirius stream). At a given galactocentric radius, the metallicity gradient as a function of the azimuthal velocity reflects the metallicity gradient in the MW along the guiding radius (or angular momentum).